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Finding the Fourth Proportional to 521.61, 781.63 and 213.29

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Solution

The fourth proportional to 521.61, 781.63 and 213.29 is: 319.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.61 : 781.63 = 213.29 : x
  2. Step 2: Convert to fraction form
    521.61/781.63 = 213.29/x
  3. Step 3: Cross multiply
    521.61x = 781.63 × 213.29
  4. Step 4: Simplify right side
    521.61x = 166,715.75
  5. Step 5: Solve for x
    x = 166,715.75/521.61
  6. Step 6: Final answer
    x = 319.61

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.